First of all - if your recording anything acoustic you need a sound proofed room (with the anti reflective walls and iso booths.) Or you need to record in a room or environment where the ambience generates the sought after reverb. Other wise its going to sound like crap.
The other things you need depend on the quality that your going for.
You can get an analog 4 track for like $50 dollars. But its a small consumer level tape, and therefore crappy audio quality.
If your going to use a "porta-studio," or digital 4 track, or 8 track, or however many you'd be better off...
However, if you use one of those - it will either need a built in CD Burner (which if it breaks your fucked (and it will im sure)) or an external CD burn thats compatable with your recorder (if your 4 track exports mp3 then the CD burner needs to import or read mp3.)
I don't really recommend either of these methods but they are viable. The second option being better then the first. With the second option you will not be able to mix and master (mixing is critical to understanding how to write modern rock music.) Now, on a larger scale I prefer a set up similar to the second, but of course it is much more elaborate.
1) Now the best option your gonna have is to get a cheap ass PC with a .7 Ghz processor (this anit shit but its fast enought to run about 14-18 tracks with heavy effects on a few tracks.)
2) Multi tracking software (if your a student Pro Tools is $300) and then theres really crappy free ones.
3) an external mixer (could be a two channel - it doesn't matter.) You need this inorder to feed the analog signal (coming from the guitar cable (high impedance)) to the PC. The mixer should feed RCAs out and those can be adapted to a 1/8" connector - which even a PC that crappy should have a sound card that has an 1/8" input.
4) You need a microphone for the guitar. I forgot that you said it was an acoutic electric right? So if you use a Mic on it this would be low impedance. Anyway you need a nice dynamic mic (only if your mixer supplies phantom power, if it doesn't then get some shitty condenser mic.) The freq response should be nice in 200-250 and 700-1k and above 5k. Probabily want uni directional with bass roll off.
5) You need a direct box for a high imped out from the guitar into the mixer. This results in a One take where there is a track on the mic and a track on a line (really you should have 2-3 mics on the acoustic and use spatial pairing.)
6) You need a kick ass mic for vox - a good prosumer mic is the C 3 (I forgot who made it, sorry)
7) You need either a drummer and a drum micing kit and a room with good ambience, or a pro tools and drum a gog, or a drum machine
8) You need a bass guitar
9) You need your PC to have a CD burner in it
10) You need CD Burning software, and possibilty an mp3 converter (if your mixing software doesn't export mp3s)
11) You need to get drunk and buy a whore
